Poly(lactic acid) membranes containing bacteriocins and EDTA for inhibition of the surface growth of gram‐negative bacteria

Films containing antibacterial reagents, ethylenediamine‐tetraacetic acid disodium salt (EDTA) and Nisaplin®, were produced by coextrusion with poly(lactic acid) in the presence of a pharmaceutical grade glycerol triacetate. The incorporation of EDTA‐Nisaplin® particles resulted in a heterogeneous biphasic structure, as revealed by scanning electronic microscopy, confocal laser microscopy, and acoustic emission tests. The inclusion of glycerol triacetate reduced the Young's modulus and tensile strength, while enhancing the flexibility and the toughness of the resulting blends. The inclusion of the plasticizer also allowed the extrusion to occur at a temperature as low as 120°C to maintain the biological activity of Nisaplin®, which in combination with EDTA, plays a synergistic effect on suppression of the growth of the Gram‐negative bacteria, E. coli O157:H7. The films thus obtained show potential as packaging materials with a wide spectrum of antimicrobial activity.